Synthetic Ferric Oxides
Excipient (pharmacologically inactive substance)
What is it?
FDA has regulatory review for color additives used in foods, drugs, cosmetics, and medical devices. Ferric (iron) oxides are coloring agents for tablets and capsules and are used in the pharmaceutical industry. Iron oxides are also commonly used in the cosmetics industry. Iron oxides for use in pharmaceutical manufacturing may also be synthetic. 
 Dave RH. Overview of pharmaceutical excipients used in tablets and capsules. Drug Topics (online). Advanstar. 10/24/2008 http://drugtopics.modernmedicine.com/drugtopics/Top+News/Overview-of-pharmaceutical-excipients-used-in-tabl/ArticleStandard/Article/detail/561047. Accessed 08/19/2011
 U.S. Food and Drug Administration. Color Additives: FDA's Regulatory Process and Historical Perspectives. Accessed 10/20/2011. http://www.fda.gov/ForIndustry/ColorAdditives/RegulatoryProcessHistoricalPerspectives/default.htm